Did You Know? Strangles is a highly contagious disease that causes swelling and painful lymph nodes that block a horse's airway causing difficult breathing. The name Strangles is used because the enlarged nodes can sometimes, though rarely suffocate a horse. One of the most common sources of infection is from water buckets previously used by infected horses. EquiSilver bucket is impregnated with special antimicrobial properties to help inhibit the surface bacteria Stretococcus Equi that causes Strangles!